Various viscous material dispensing systems or apparatus, such as, for example, systems or apparatus for dispensing and distributing adhesive or resin materials, whereby the adhesive or resin materials can be applied to or deposited upon a particular substrate, are of course well known. One such known system or apparatus is disclosed within U.S. Pat. No. 5,622,315 which was issued on Apr. 22, 1997 to the inventors Keane et al. As shown in FIG. 6 of the patent, the system or apparatus comprises an upper die half 12, a lower die half 14, a mouthpiece or die plate 22, and a shim 16 which, is interposed between and separates the upper and lower die halves 12, 14 so as to define a die opening 20 therebetween. The mouthpiece or die plate 22 is secured to the upper die half 12 by means of a plurality of threaded screws 124.
Another material dispensing system or apparatus for likewise dispensing and distributing materials of the afore-noted type for deposition upon a substrate is disclosed within U.S. Pat. No. 5,478,224 which was issued on Dec. 26, 1995 to the inventor McGuffey, such patent being assigned to the assignee of the present invention. As best appreciated from FIGS. 2 and 3 of the patent, the system or apparatus similarly comprises a glue block or adhesive manifold 66, a mouthpiece or die plate 86, and a shim 88 interposed between the bottom surface of the glue block or adhesive manifold 66 and the mouthpiece or die plate 86. A plurality of fasteners, illustrated but not numbered, fixedly secure the mouthpiece or die plate 86, and the shim 88, upon the underside of the glue block or adhesive manifold 66.
FIG. 1 is also illustrative of a conventionally known die plate generally indicated by the reference character 10. As is known, the die plate 10 comprises a plurality of laterally spaced material or fluid deposition channels 12, into which, for example, the viscous fluid or material is initially charged or deposited, and a laterally extending distribution channel 14 which fluidically interconnects the plurality of fluid deposition channels 12. A doctor blade or material application surface 16 is formed upon a leading edge portion of the die plate 10, and a recessed lip region 18 is defined within the leading edge portion of the die plate 10 so as to permit defined or precisely controlled fluidic communication between the laterally extending distribution channel 14 and the doctor blade or material application surface 16. A plurality of through bores 20 are defined within the die plate 10 so as to permit the die plate 10 to be fixedly secured to a glue block, adhesive manifold, or the like, by means of suitable threaded bolt fasteners, or the like, not shown.
FIG. 2 illustrates another conventionally known die plate which is similar to the die plate 10 of FIG. 1 and is generally indicated by the reference character 110. In view of the similarity of the die plate 110 of FIG. 2 to the die plate 10 of FIG. 1, like or corresponding parts of the die plate 110 have been designated by similar reference characters, within the 100 series, however, further detailed description of the same has been omitted herefrom in view of the fact that one of ordinary skill in the art will readily appreciate the various similar operative components or elements of the die plate 110.
In view of the threaded bolt fastening of the various die plates, or the like, to the associated support structures as disclosed within the patents of Keane et al. and McGuffey, as well as the die plates 10 and 110 illustrated in FIGS. 1 and 2, and in particular, as illustrated in FIGS. 2B and 3 of Keane et al. and McGuffey, respectively, it is readily appreciated that the number of bolt fasteners 124, for example, as shown in Keane et al., as well as those not numbered in McGuffey, which are used to fasten the die plates or the like to their support structures, is considerable. Accordingly, when a particular die plate is to be exchanged or replaced so as to, for example, alter the adhesive patterns or replace a worn die, the exchange or replacement operation is quite time-consuming and labor intensive in view of the considerable number of bolt fasteners which are required to be completely removed from the support structure in connection with the removal of the particular or original die plate, and subsequently, the replacement or reinsertion of such bolt fasteners back into the support structure in order to secure the newly exchanged or replacement die plate upon the support structure.
FIGS. 3 and 4 illustrate another conventional die plate assembly system or apparatus, manufactured by the NORDSON CORPORATION, which was designed to overcome the operative drawbacks characteristic of the die plates illustrated within FIGS. 1 and 2, as well as those illustrated within the foregoing patents to Keane et al. and McGuffey. More particularly, with reference initially being made to FIG. 3, such apparatus or system 210 is seen to comprise a head 212 within which is mounted a cartridge heater 214. An adhesive manifold 216, through which a supply of adhesive 218 is conveyed, mounted upon the head 212, and a doctor blade assembly 220, which is shown enlarged in FIG. 4, is adapted to be mounted upon the head 212. As shown in FIG. 4, the doctor blade assembly 220 comprises a pair of doctor blades 222, 224 between which is mounted a shim 226, the doctor blades 222, 224 being fixedly secured together by means of a threaded fastener 228. In order to mount the doctor blade assembly 220 upon the head 212, a substantially C-shaped clamp 230 is bolted to head 212 by means of one or more bolt fasteners 232. Consequently, as may be appreciated from FIG. 3, the doctor blade assembly 220 is clamped between a lower leg portion 234 of the C-clamp 230 and a lower dependent portion 236 of the head 212. Accordingly, when it is desired to remove or exchange the die in order to change the adhesive patterns or replace a worn die, the one or more bolt fasteners 232 are simply loosened, but not removed, and the doctor blade assembly 220 is thereby permitted to be readily, simply, and quickly removed, and a new doctor blade assembly 220 is likewise able to be readily, simply, and quickly inserted. Bolt fasteners 232 are then re-tightened and the system or apparatus is back on line.
While the aforenoted NORDSON system thus overcomes the operative drawbacks characteristic of the prior art of Keane et al. and McGuffey, as well as the die plates 10 and 110 shown in FIGS. 1 and 2, in that the doctor blade assembly can be easily and rapidly exchanged or replaced without operator personnel having to perform the aforenoted time-consuming and tedious operations of completely removing the bolt fasteners mounting the die plates upon the support structure, the NORDSON system or apparatus exhibits its own operative drawbacks and has therefore not proven to be entirely satisfactory. For example, in view of the fact that the doctor blade assembly 220 is clamped between the C-clamp 230 and the head 212, as opposed to being bolted upon the head 212, the doctor blade assembly 220 may not be precisely positioned or oriented upon the head 212 whereby the resulting adhesive patterns, to be applied to a particular substrate, may not be achieved. In addition, if the doctor blade assembly 220 is not precisely or properly positioned or oriented upon the head 212, the conveyed adhesive 218 will, for example, become interposed, or penetrate the surface interface defined, between the doctor blade assembly 220 and the lower end or dependent portion 236 of the head 212 whereby, again, proper dispensing, application, or distribution of the adhesive onto or upon the substrate will be adversely affected.
Accordingly, there is a need in the art for a new and improved die plate or shim element or component whereby all of the aforenoted drawbacks and disadvantages characteristic of the prior art die plate or shim assemblies can be overcome or rectified.